JPH0490462A - Freezer capacity evaluation device - Google Patents

Abstract

PURPOSE:To carry out economic, continuous, and simple capacity estimation by comparing the heating value of cooled water computed by a cooled water arithmetic operation means with a reference heating value in conformity with the input power of a refrigerating machine entered by a data input means, and estimating the presence of capacity drop. CONSTITUTION:Each data, such as input power (w) of a refrigerating machine 1, the temperature To.Ti of cooled water inlet and outlet, the discharge pressure Po, and suction pressure Pi of a cooling pump 2 is entered into a capacity estimation device 4 from the refrigerating machine 1 and the cooling pump 2. Then, the data is inputted from a data input section 41 to a cooled water heating value arithmetic operation section 42 where the flow rate (f) is read from the characteristics of head (h) versus flow rate (f) of the cooling pump 2. The data thus read is multiplied by a differential temperature between the inlet and outlet temperatures To.Ti of the refrigerating machine so as to compute the heating value Q of cooled water. On the other hand, when the data is inputted from a data input section 41 into a capacity drop estimation section 44, a reference heating value (c) is read out from the characteristic of the heating value (Q) versus input power (w). Then, the heating value Q from the cooled water arithmetic operation section 42 is compared with this reference value 4, which makes it possible to estimate the presence of capacity drop and hence indicates the result on a display section 46.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an apparatus for evaluating the capacity of a refrigerator, and in particular, to an apparatus for evaluating the capacity of a refrigerator, and in particular, to enable the capacity evaluation to be carried out economically, continuously, and easily. The present invention relates to a capacity evaluation device for a refrigerator.

(Prior Art) Conventionally, the performance of a refrigerator, which is a heat source device for heating and cooling a building, has been evaluated.

The purpose of this chiller capacity evaluation is not only to evaluate the initial capacity, but also to continuously monitor the maintenance status of capacity. In other words, it is a necessary measurement item in order to understand the deterioration status of the chiller capacity and formulate an appropriate maintenance plan.

By the way, a method for evaluating the performance of this type of refrigerator is to measure the calorific value of the generated cold water. Therefore, we had to install cold water inlet/outlet thermometers and flow meters. Among these, flowmeters are relatively expensive and therefore impose a heavy economic burden on installation. Recently, there have been cases in which a flowmeter is not installed, and in these cases, a flowmeter is temporarily installed for testing, which increases testing man-hours and testing costs.

(Problems to be Solved by the Invention) As described above, in the past, it cannot be said that capacity evaluation of refrigerators has been fully utilized. Although there has been a strong desire for a new method to emerge, the reality is that this type of ability evaluation device has not yet been realized.

SUMMARY OF THE INVENTION An object of the present invention is to provide an extremely reliable refrigerating machine performance evaluation device that can economically, continuously, and easily perform refrigerating machine performance evaluation.

[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above object, the present invention provides an apparatus for evaluating the capacity of a refrigerator equipped with a cold water pump that passes cold water.
A data input means for inputting each data of input power, cold water inlet/outlet temperature, cold water pump discharge pressure, and suction pressure of the refrigerator to be evaluated, and the chilled water inlet/outlet temperature of the refrigerator and the cold water pump input by the data input means. chilled water calorie calculating means for calculating the chilled water calorie from the pump characteristics of the chilled water pump based on each data of the discharge pressure and suction pressure of the chilled water pump; A capacity reduction estimating means for estimating the presence or absence of a capacity reduction by comparing the amount of heat according to the input power of the chiller with a reference calorie, and further a display for displaying the estimation result by the capacity reduction estimation means, if necessary. It is constructed by adding means.

(Function) Therefore, in the chiller capacity evaluation device according to the present invention, each data of input power, chilled water inlet/outlet temperature, chilled water pump discharge pressure, and suction pressure during operation of the chiller is inputted via the data input means. data is collected as time series data. By storing head vs. flow rate characteristics in a database as the pump characteristics of the cold water pump, firstly, using the collected discharge pressure and suction pressure of the cold water pump, the head -
(Discharge pressure Kerr suction pressure) The flow rate is derived by giving the lift from the formula XIO (m), and the chilled water heat amount is calculated by multiplying this by the temperature difference between the chilled water inlet and outlet of the refrigerator.

On the other hand, by storing the heat value vs. input power characteristics in a database as a reference heat amount, the reference heat amount is derived using the collected chiller input power, and then this reference heat amount is compared with the calculated chilled water heat amount. Then, the degree of decrease in the amount of heat of the chilled water relative to the reference amount of heat is estimated and evaluated as a decrease in capacity, and this estimation result is displayed as necessary.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a configuration example when the present invention is applied to a refrigerator for heating and cooling a building or a factory. In FIG. 1, a refrigerator 1 to be evaluated is composed of basic elements such as an evaporator 11, a compressor 12, a condenser 13, and a fat expansion valve 14. A cold water tank 3 is provided to store the cold water generated in the cold water tank 3.

On the other hand, the performance evaluation device 4 according to this embodiment includes a data input section 41, a chilled water calorie calculation section 42, a pump characteristic database 43, a performance reduction estimation section 44, a reference calorie database 45, and a display section 46. are doing.

Here, the data input unit 41 inputs the input power W of the refrigerator 1,
Cold water inlet/outlet temperature To'T11 Cold water bomb 2 discharge pressure P
0. and suction pressure P1 are input. Further, the chilled water heat amount calculation unit 42 calculates the chilled water inlet/outlet temperatures T0, T1, .
Discharge pressure P of cold water pump 2. , and the suction pressure P1, the cold water heat amount Q is calculated from the pump characteristics of the cold water pump 2 stored in the pump characteristics database 43. Furthermore, the pump characteristic database 43 is configured based on design data etc. in advance for the cold water pump 2.
As the pump characteristics, the required head (h) vs. flow rate (f) characteristics are stored.

On the other hand, the capacity reduction estimating unit 44 reads a reference calorie C from the input power P0 of the refrigerator 1 inputted by the data input unit 41 from the calorie vs. input power characteristic stored in the reference calorie database 45, and reads this reference calorie C and the chilled water heat quantity Q calculated by the chilled water heat quantity calculating section 42 are compared to estimate whether or not the performance has decreased. Further, the reference heat amount database 45 stores required heat amount (Q) vs. input power (w) characteristics as a reference heat amount in advance based on design data or the like. Furthermore, the display section 46 displays the estimation results by the performance reduction estimating section 44.

Next, the capacity evaluation device 4 for the refrigerator 1 configured as described above will be described.
The operation will be explained using the flow diagram shown in FIG.

In FIG. 1, from the refrigerator 1 and the cold water pump 2, input power W of the refrigerator 1, cold water input/output humidity temperature 0, T2. Discharge pressure P0 of cold water pump 2. and suction pressure P+ are input to the performance evaluation device 4. Then, the ability evaluation device 4 receives these data and executes the processing shown in FIG. 2.

That is, among the respective data input to the data input section 41, the cold water inlet/outlet temperature T0 and T1, and the discharge pressure P of the cold water pump 2. , and suction pressure P, are input to the cold water calorific value calculation section 42. Then, in the cold water calorie calculation unit 42, first, the collected discharge pressure P0 and suction pressure P0 of the cold water pump 2 are calculated.
+ is used to read out the cold water flow jlf from the head (h) versus flow rate (f) characteristics of the cold water pump 2 as shown in FIG. cold water inlet/outlet temperature T.・Cold water heat quantity Q is calculated by multiplying the temperature difference between T and T.

On the other hand, among each data input to the data input section 41,
The input power W of the refrigerator 1 and the chilled water calorific value Q calculated by the chilled water calorific value calculation unit 42 are input to the capacity reduction estimation unit 44 . Then, the capacity reduction estimating unit 44 first uses the input power P of the refrigerator 1 to calculate the amount of heat (Q) as shown in FIG. 4 stored in the reference amount of heat database 45.
The reference heat amount C is read out from the input power (W) characteristic, and then this reference heat amount C and the chilled water heat amount Q from the chilled water heat amount calculating section 42 are read out.
The presence or absence of ability decline can be estimated by comparing
The estimation results are displayed as messages or graphs on the display section 4.
6. In this case, the comparison method is that if the ratio (Q/c) between the chilled water calorie Q and the reference calorie C is below a certain threshold value g ((Q/c)<j2), It is estimated that the ability has decreased.

FIG. 5 is a diagram showing an example of ability characteristics.1. The figure shows the cold water calorific values Q1 to Q5 and the reference calorific values 01 to C9 at the time of ~t5. That is, since the load conditions differ at each point in time, it is not possible to estimate the capacity decline based on the amount of heat, so it is estimated by comparing it with a reference value, and threshold determination, trend analysis, etc. are performed.

As described above, in the refrigerator capacity evaluation device of this embodiment, the cold water inlet/outlet temperature T0 of the refrigerator 1 to be evaluated is
・Calculate the chilled water calorie Q from the pump characteristics of the chilled water pump 2 based on T I, the discharge pressure P O+ of the chilled water pump, and the suction pressure P, and calculate the chilled water calorie Q based on the chilled water calorie Q and the input power W of the refrigerator 1. Since the amount of heat is compared with the standard amount of heat C to estimate whether or not there is a decrease in performance, and the result of this estimation is displayed, the following various effects can be achieved.

(a) It is now possible to understand the capacity of chiller 1 without installing a flow meter as in the past, and by managing it in chronological order, it greatly contributes to the operation plan and maintenance plan of chiller 1. be able to.

(b) If a decrease in capacity is evaluated, the chilled water flow rate may decrease due to an abnormality on the chilled water pump 2 side, but in this example, since the pump characteristics of the chilled water pump 2 are referred to, It is also possible to estimate the location of the abnormality.

In other words, the correct evaluation of ability decline is
As a result, this will lead to significant economic and safety benefits.

It should be noted that the present invention is not limited to the embodiments described above, but can also be implemented in the following manner.

(a) In the above embodiment, the display section 46 is not necessarily essential to the present invention.

(b) In the above embodiment, it is also possible to configure the capacity reduction estimating unit 44 to have a function of not only estimating the current capacity but also predicting the maintenance time, so that the maintenance time can be predicted. be.

FIG. 5 is a diagram showing a trend graph of the performance deterioration evaluation value (Q/c), and FIG. 6 is a flowchart showing processing details for predicting maintenance time from this trend graph. In FIG. 5, the ability decline evaluation value (Q/c) indicates the signs of ability decline at a threshold value g. The trend graph is extended from the time t5 detected at , and the time 1-, which becomes (Q/c-II), can be regarded as the maintenance time.

As a result, if maintenance timing can be predicted, maintenance can be carried out in a planned manner, and the refrigerator 1 can be operated for a long life while maintaining the required capacity.

(c) In the above embodiment, the operating point of the refrigerator 1 is corrected based on the chilled water heat quantity Q1 by the chilled water heat quantity calculation unit 42 or the estimation result by the capacity reduction estimation unit 44 (specifically, for example, The opening degree of the vane may be corrected to adjust the flow rate of the medium.

[Effects of the Invention] As explained above, according to the present invention, there is provided an extremely reliable refrigerator performance evaluation device that can economically, continuously, and easily perform refrigerator performance evaluation. can.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the capacity evaluation device according to the present invention applied to a refrigerator, Fig. 2 is a flow diagram for explaining the operation of the same embodiment, and Fig. 3 is a diagram of a cold water pump. Figure 4 is a diagram showing an example of head vs. flow rate characteristics; Figure 4 is a diagram showing an example of chiller heat quantity vs. input power characteristics; Figure 5 is for explaining the processing content when the present invention is applied to predicting maintenance timing. FIG. 6 is a flow diagram for explaining the operation of the processing contents in FIG. DESCRIPTION OF SYMBOLS 1... Refrigerator, 11... Evaporator, 12... Compressor, 13... Condenser, 14... Expansion valve, 2... Cold water pump, 3... Cold water tank, 4 ...Ability evaluation device, 41
...Data input section, 42...Cold water calorie calculation section, 43
. . . Pump characteristics database, 44 . Applicant's agent Patent attorney Takehiko Suzue

Claims (3)

[Claims] (1) In a device that evaluates the capacity of a refrigerator equipped with a cold water pump that passes cold water, each data of the input power of the refrigerator to be evaluated, the temperature of the cold water inlet and outlet, the discharge pressure of the cold water pump, and the suction pressure. Calculate the amount of heat of chilled water from the pump characteristics of the chilled water pump based on the data of the chilled water inlet/outlet temperature of the refrigerator, the discharge pressure of the chilled water pump, and the suction pressure inputted by the data inputting means. a chilled water calorie calculating means for calculating the chilled water calorie, and comparing the chilled water calorie calculated by the chilled water calorie calculating means with a reference calorie according to the input electric power of the refrigerator input by the data input means to estimate the presence or absence of a decrease in capacity. A capacity evaluation device for a refrigerator, comprising: capacity reduction estimation means. (2) The chiller capacity evaluation device according to claim (1), further comprising a display means for displaying the estimation result by the capacity reduction estimation means. (3) According to claim (1), the capacity reduction estimating means is configured to estimate that the capacity has decreased when the ratio of the chilled water calorie to the reference calorie is less than or equal to a predetermined value. A capacity evaluation device for the refrigerating machine described above.